Question

$aA+bB\to Product,dx/dt=k\left[A{]}^a\right[B{]}^b$. If conc of A is doubled, rate is four times. If conc. of B is made four times, rate is doubled. What is relation between rate of disappearance of A and that of B?

• A. {-d[A]/dt} = {-d[B]/dtK
• B. {-d[A]/dt} =-4 {d[B]/dt}
• C. -4{d[A]/dt} = {d[B]/dt}
• D. None of these

Answer 1

The correct option is B {-d[A]/dt} =-4 {d[B]/dt}

-d[A]/dt = -4d[B]/dt

Concentration of A is doubled rate becomes 4 times and concentration of B four times then rate becomes doubled

Thus -d[A]/2dt = -2.d[B]/dt

-d[A]/dt = -4d[B]/dt